A seat belt assembly, commonly referred to as a passenger restraint system, is a type of harness system designed to restrain an occupant of an automobile or other motorized vehicle against inadvertent movement that may result from a collision or a sudden stop. Conventional seat belt systems employ a belt buckle or like element, which is positioned inboard from the occupant seating position, for engagement with a mating latch plate or fastener, generally provided outboard from the occupant seating position. Engagement of the buckle with the latch plate provides a belt or belt webbing across the body of a seated occupant for restraining the occupant against abrupt movement from the seat.
Due to the nature of the loads on the seat belt assembly during vehicle impact, the assembly has traditionally been mounted directly to the vehicle structure, generally utilizing a three-point attachment configuration. In this regard, the belt strap or webbing is attached to the vehicle floor pan by a belt retractor mounted rigidly thereto. The belt extends upwardly along the B-pillar and through a support member (i.e., a D-ring) mounted near the top of the B-pillar. The strap then extends downward, and is secured at a second end to the vehicle pan adjacent to the retractor. The latch plate is supported by the belt webbing and adapted to slide along the belt between the end anchored to the vehicle floor and the support-ring. The belt buckle is conventionally mounted to the vehicle pan by a buckle strap which extends through a gap between the bottom cushion and either the middle console or the back cushion of the seat. In a two-point attachment configuration (i.e., wherein a lap belt is provided), the second end of the belt webbing is generally rigidly secured to the latch plate instead of the floor pan, thereby eliminating a third attachment point.
It is also reasonable to mount the seat belt assembly directly to the vehicle seat assembly. By way of example, the seat belt retractor is affixed directly to the seat platform (i.e., the base of the seat frame.) The strap then extends upwards along the back-frame of the upper seat cushion and passes through a guide or upper support member mounted at the top of the seat frame, adjacent the head rest. The strap then extends downward, and is connected to the seat frame adjacent to the retractor. Conventional vehicle seats may be, by way of example, a bucket seat or a bench seat.
In the prior art, the buckle, belt, and webbing has typically been secured to the vehicle structure or seat frame via a seat belt anchor. Such anchor mechanisms typically consist of a single plate member with an oblong first opening for receiving the belt webbing, belt retractor, or buckle strap, and a circular second opening for attachment to the vehicle structure of seat frame. The second opening is generally sized to receive a plastic bushing or washer to provide a low friction surface for a fastener (i.e., a stepped bolt, rivet, stud, etc.) During installation, the fastener is received by and secured to the vehicle structure, which can be the seat frame, vehicle floor pan, a B or C pillar, or other part of the vehicle. Anchors of the prior art generally have to be installed into the cab structure prior to completion of the cab structure.